This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A193741 #5 Mar 30 2012 18:57:38 %S A193741 1,1,1,3,3,1,9,9,4,1,19,19,10,4,1,34,34,20,10,4,1,55,55,35,20,10,4,1, %T A193741 83,83,56,35,20,10,4,1,119,119,84,56,35,20,10,4,1,164,164,120,84,56, %U A193741 35,20,10,4,1,219,219,165,120,84,56,35,20,10,4,1,285,285,220,165 %N A193741 Mirror of the triangle A193740. %C A193741 A193741 is obtained by reversing the rows of the triangle A193740. %F A193741 Write w(n,k) for the triangle at A193740. The triangle at A193741 is then given by w(n,n-k). %e A193741 First six rows: %e A193741 1 %e A193741 1....1 %e A193741 3....3....1 %e A193741 9....9....4....1 %e A193741 19...19...10...4...1 %e A193741 34...34...20...10..4..1 %t A193741 z = 12; %t A193741 p[0, x_] := 1 %t A193741 p[n_, x_] := n + Sum[(k + 1) x^(n - k), {k, 0, n - 1}] %t A193741 q[n_, x_] := p[n, x] %t A193741 t[n_, k_] := Coefficient[p[n, x], x^(n - k)]; %t A193741 t[n_, n_] := p[n, x] /. x -> 0; %t A193741 w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1 %t A193741 g[n_] := CoefficientList[w[n, x], {x}] %t A193741 TableForm[Table[Reverse[g[n]], {n, -1, z}]] %t A193741 Flatten[Table[Reverse[g[n]], {n, -1, z}]] (* A193740 *) %t A193741 TableForm[Table[g[n], {n, -1, z}]] %t A193741 Flatten[Table[g[n], {n, -1, z}]] (* A193741 *) %Y A193741 Cf. A193740. %K A193741 nonn,tabl %O A193741 0,4 %A A193741 _Clark Kimberling_, Aug 04 2011